Atoms

To a subtle mind, a model of a crystal.

We shall never get people whose time is money to take much interest in atoms.
— Samuel Butler (1835 – 1902), Notebooks

To understand the very large, we must understand the very small.
— Democritus (470 – 380 BCE)

Atoms move in the void and catching each other up jostle together, and some recoil in any direction that may chance, and others become entangled with one another in various degrees according to their shapes and sizes and positions and orders, and they come together and thus the coming into being of composite things is effected.
— Simplicius (c. 400 BCE), De Caelo

The particular properties of elastic fluids are as follows: 1. they are heavy; 2. they expand in all directions unless they are restrained; 3. they are continually more and more compressed when the force of compression increases. Air is a body of this sort …

Consider a cylindrical vessel set vertically, and a movable piston in it, on which is placed a weight. Let the cavity contain very minute corpuscles, which are driven here and there with a very rapid motion. These corpuscles, when they strike the piston, and hold it up by their repeated impacts, form an elastic fluid which will expand by itself if the weight is removed or made smaller … [The fluid] will be condensed if the weight is increased … whether the corpuscles are at rest or moving, they do not lose their weight, so that the bottom sustains not only the weight but the elasticity of the fluid. Such therefore is the fluid that we shall substitute for air. Its properties agree with those that we have already assumed for elastic fluids, and by them we shall explain other properties which have been found for air and shall point out others which have not yet been sufficiently considered.
— Daniel Bernoulli (1700 – 1782), discussing atoms and their properties.

Atoms tormented on this ball of clay,
The sport of death, of hazard’s strokes the prey,
Yet thinking atoms, whose clear eyes
Guided by thought have measured out the skies,
Into the infinite we fling our gaze
Yet cannot see ourselves nor count the days …
— François Marie Arouet de Voltaire (1694 – 1778)

The Atoms of Democritus
And Newton’s Particles of Light
Are sands upon the Red sea shore
Where Israel’s tents do shine so bright.
— William Blake (1757 – 1827), Complete Blake (Oxford Paperback, 1974), 418.

1.         From nothing comes nothing. Nothing that exists can be destroyed. All changes are due to the combination and separation of molecules.

2.         Nothing happens by chance. Every occurrence has its cause from which it follows by necessity.

3.         The only existing things are atoms and empty space; all else is mere opinion.

4.         The atoms are infinite in number and infinitely various in form; they strike together and the lateral motions and whirlings which thus arise are the beginnings of worlds.

5.         The varieties of all things depend upon the varieties of their atoms, in number, size, and aggregation.

6.         The soul consists of fine, smooth, round atoms like those of fire. These are the most mobile of all. They interpenetrate the whole body and in their motions the phenomena of life arise.
— Robert Andrews Millikan quotes these words of Democritus in his book The Electron, saying that they are from [Sir John] Tyndall.

It clearly follows that no rest is given to the atoms in their course through the depths of space … some of them bounce far apart after a collision while others recoil only a short distance … Those … that move freely through larger tracts of space, springing far apart and carried far … provide for us thin air and blazing sunlight …

Observe what happens when sunbeams are admitted into a building and shed light on its shadowy places. You will see a multitude of tiny particles mingling in a multitude of ways in the empty space within the light of the beam, as though ever contending in everlasting conflict, rushing into battle rank upon rank with never a moment’s pause in a sequence of rapid unions and disunions.
— Titus Lucretius Carus (c. 99 – 55) BCE, De Rerum Natura (“About Natural Things”).

When any body exists in the elastic state, its ultimate particles are separated from each other to a greater distance than in any other state; each particle occupies the centre of a comparatively large sphere, and supports its density by keeping all the rest, which by their gravity or otherwise, are disposed to encroach upon it, at a respectable distance.

Chemical analysis and synthesis go no further than to the separation of particles one from another, and to their reunion. No new creation or destruction of matter is within the reach of the chemical agency. We might as well attempt to introduce a new planet into the solar system, or to annihilate one already in existence, as to create or destroy a particle of hydrogen. All the changes we can produce consist in separating particles that are in a state of cohesion or combination, and joining those that were previously at a distance.

— John Dalton, A New System of Chemical Philosophy, 1808.

They may say what they like. Everything is organised matter.
— Napoleon Bonaparte (1769 – 1821)

While examining the form of these particles immersed in water, I observed many of them very evidently in motion; their motion consisting not only of change of place in the fluid manifested by alterations in their relative positions, but also not infrequently of a change of form in the particle itself; a contraction or a curvature taking place repeatedly about the middle of one side, accompanied by a corresponding swelling or convexity on the opposite side of the particle. In a few instances, the particle was seen to turn on its longer axis. These motions were such as to satisfy me, after frequently repeated observation, that they arose neither from currents in the fluid, nor from its gradual evaporation, but belonged to the particle itself …

Having found motion in the particles of the pollen of all the living plants which I had examined, I was led to enquire whether this property continued after the death of the plant, and for what length of time it was retained.

In plants, either dried or immersed in spirit [ethanol] for a few days only, the particles of pollen of both kinds were found in motion equally evident with that observed in the living plant; specimens of several plants, some of which had been dried and preserved in an herbarium for upwards of twenty years, and others not less than a century, still exhibited the molecules or smaller spherical particles in considerable numbers, and in evident motion, along with a few of the larger particles, whose motions were much less manifest, and in some cases not observable …

Rocks of all ages, including those in which organic remains had never been found, yielded the molecules in abundance. Their existence was ascertained in each of the constituent minerals of granite, a fragment of the Sphinx being one of the specimens examined.
— Robert Brown (1773 – 1858), Miscellaneous Botanical Works, volume 1, 465 ff.

I am now convinced that we have recently become possessed of experimental evidence of the discrete or grained nature of matter for which the atomic hypothesis sought in vain for hundreds and thousands of years. The isolation and counting of gaseous ions on the one hand … . and on the other the agreement of the Brownian movements with the requirements of the kinetic hypothesis … . justify the most cautious scientist in now speaking of the experimental proof of the atomic theory of matter. The atomic hypothesis is thus raised to the position of a scientifically well-founded theory.
— Wilhelm Friedrich Ostwald (1853 – 1932), Grundriss der allgemeinen Chemie (4th ed., 1909),

An atom is the smallest possible piece of matter that can take part in normal chemistry. No one has ever seen, nor probably ever will see, an atom, but that does not deter the physicist from trying to draw a plan of it, with the aid of such clues to its structure as he has.
— Maria Goeppert Mayer (1906 – 1972), ‘The Structure of the Nucleus’, Scientific American Reader (1953), 116.

In fact it may be logically impossible for anyone to be able to correctly visualize certain physical systems, such as atoms, because they contain features that simply do not exist in the world of our experience.
— Paul Davies, The Mind of God, Penguin Books, 1990, 18.

There have been almost innumerable attempts to reduce the differences between atomic weights to regularity by contriving some formula which will express the numbers which represent the weights with all their irregularities. Needless to say, such attempts have in no way been successful.
— Sir William Ramsay (1852 – 1916), address to the British Association, Toronto, 1897.

… although the [mass spectral] lines are broad … their edges, particularly their left-hand edges, are remarkably sharp, so that measurements of a reasonably good line from the register spot repeat to a twentieth of a millimetre with certainty. Hence for accurate determination of unknown lines only two assumptions need be made. Firstly, that the masses of the reference lines are known, and secondly that, whatever the function connecting displacement with mass, any two positions on the spectrum being taken, the ratio of any two masses giving lines in these positions will be constant.
— Francis William Aston (1877 – 1945), Philosophical Magazine, Sixth Series, 38, 707-714, 1919.

The first support of the isotope theory among non-radioactive elements was given by the anomalous behaviour of the inactive gas neon, when analysed by Sir J. J. Thomson’s method of positive rays … This peculiarity was that whereas all elements previously examined gave single, or apparently single, parabolas, that given by neon was definitely double. The brighter curve corresponded roughly to an atomic weight of 20, the fainter companion to one of 22, the atomic weight of neon being 20.20.
— Francis William Aston (1877 – 1945), address before the Royal Institution, 1921.

 

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